A $240 V, 200 W$ bulb is connected to a $210 V$ source. Determine the bulb's power consumption.

Electric Power: Electrical power, i.e. the rate at which electrical energy is converted into other kinds of energy

$P=\frac{W}{t}=VI=I^{2}R=\frac{V^2}{R}$

Where V=  Potential difference, R=  Resistance, and I= current.

Given - Potential difference V= 240V, the power of the bulb P= 200W  and the actual voltage

$\left(V^{\text{'}}\right)=210 \mathrm{V}$

The calculation for the bulb's resistance is as follows:

$\Rightarrow R=\frac{V^2}{P}=\frac{(240{)}^2}{200}=288\Omega$

how much electricity the lightbulb uses.

$\Rightarrow P=\frac{V^2}{R}=\frac{(210{)}^2}{288}=153 \mathrm{W}$